Impact assessment of the introduction of Cichla kelberi in a large Neotropical reservoir and its lateral lagoons (Upper Paraná River Basin, Brazil)

Abstract

This study aimed to understand how the introduction of Cichla kelberi in Rosana Reservoir (Paranapanema River) affected the native ichthyofauna. Data on the structure of the small fish fauna assemblage were obtained before and after the introduction of this carnivorous species. Samplings were carried out in The order Characiformes was the most abundant, followed by Perciformes and Siluriformes. Comparative analyses, before and after the introduction, could not demonstrate significant changes in composition, richness, abundance, biomass, mean length and diversity of fish. Aquatic insects were the main feeding item of C. kelberi, followed by tetragonopterinae fish. Cannibalism was recorded during the whole study period. The results showed that Cichla cannot deeply affect the ichthyofauna assemblages of a large Neotropical reservoir, at least in a short or medium term period after its introduction. The results also allowed concluding that the introduction of C. kelberi in the reservoir is in the phase 3. In this phase, the specie can survive and reproduce in the new environment; however it is not totally established and disseminated. The reasons for the fact that Cichla is still not dominant in Rosana Reservoir could be related to feeding competition, high rate of cannibalism and the presence of large amount of aquatic macrophytes (refuge zones). In spite of the results, the continuous monitoring of the role of non-native species on the local fish fauna is absolutely necessary because the impacts caused by colonization of this undesirable species can be magnified by complex processes, usually correlated with other environmental disturb, especially the negative effects of damming.Keywords: Paranapanema River, Rosana reservoir, non-native fish, biodiversity, ecological impact. Avaliação do impacto da introdução da

Reduced genetic diversity and the success of the invasive peacock bass (Cichliformes: Cichlidae)

“…In this study, C. kelberi and C. monoculus were considered as valid species, as most of the sequences of Cichla deposited in the GenBank followed Kullander andFerreira (2006) classification. Braga, 2003;Ferrareze and Nogueira, 2015;Marques et al, 2016), as also in North America, Africa and Asia (Golani et al, 2019;Sastraprawira et al, 2020), and represent a potential threat to the native fish fauna.…”

Estrutura Populacional de Espécies do Gênero Cichla (Osteichthyes: Cichliformes) Introduzidas em Diferentes Regiões Brasileiras – uma Revisão Bibliográfica

“…Por outro lado, no reservatório de Cachoeira Dourada, foi observado que as populações tendem ao equilíbrio quando estão bem estabelecidas e podem partilhar funções com outras espécies nativas carnívoras, visto que o reservatório conta com uma variedade de ambientes para forrageamento (Luiz et al, 2011). Ademais, o canibalismo é comum em ciclídeos (Novaes et al, 2004;Villares & Gomiero, 2010) e pode contribuir para o controle da densidade populacional (Ferrareze & Nogueira, 2015).…”

“…Esses impactos negativos resultaram na desestruturação e simplificação funcional das comunidades locais, causando declínio de funções ecossistêmicas como a mobilização e a transferência de energia (Leal et al, 2021). Por outro lado, no curto a médio prazo (até 5 anos) a introdução dos tucunarés não apresentou efeitos significativos na ictiofauna deste reservatório (Ferrareze & Nogueira, 2015). Apesar de reduzir a abundância das principais espécies e a biomassa de peixes imediatamente após a sua introdução, quando sua abundância era elevada, C. kelberi não era a espécie dominante no reservatório de Rosana durante o período avaliado, principalmente devido à competição por alimentos, elevadas taxas de canibalismo e ao refúgio das presas nos bancos de macrófitas (Ferrareze & Nogueira, 2015).…”

Socioeconomic aspects of sport fisheries in a neotropical reservoir

“…Another negative effect highlighted by many authors is related to ethical issues associated with animal welfare (Chaves & Freire, 2012;Caminhas, 2015), mainly due to the practice of "catch-and-release", which presents the possibility of causing suffering to fish and can lead to the mortality of the individuals that are subjected to this modality (Cooke & Sneddon, 2007;Thomé-Souza, 2014;Barrocoet et al, 2018). In addition, sport fishing has been determined to be one of the main vectors for introducing non-native species into inland waters, which has been well documented in the literature (Ribeiro et al, 2017;Pelicice & Agostinho, 2009;Vitule et al, 2014;Pelicice et al, 2017;Gubiani et al, 2018), and the effects of non-native species on local biodiversity are also well known (Agostinho et al, 2005;Dudgeon et al, 2006;Ferrareze & Nogueira, 2015).…”